CVE-2026-69249

Name	CVE-2026-69249
Description	python-cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. Prior to 49.0.0, when resolving invalid certificate chains that include duplicate copies of self-signed certificates, the processing recursively invokes the same candidate, leading to an exponential blowup. Although the limitation that the chain depth cannot exceed a specified maximum depth prevents unbounded recursion and guarantees termination, an attacker-controlled certificate chain can lead the processing to easily take more than 5s to reject in testing. This amplification could form the basis for a resource exhaustion denial of service attack. The core issue arises in the recursive nature of build_chain_inner, which does not de-duplicate against previously analyzed candidates. As the correctness of validation is not affected, the integrity of a system cannot be compromised through this vector, only its availability. This issue is fixed in 49.0.0.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
python-cryptography (PTS)	bullseye	3.3.2-1	vulnerable
	bullseye (security)	3.3.2-1+deb11u1	vulnerable
	bookworm	38.0.4-3+deb12u1	vulnerable
	bookworm (security)	38.0.4-3~deb12u1	vulnerable
	trixie	43.0.0-3+deb13u1	vulnerable
	forky	47.0.0-1	vulnerable
	sid	49.0.0-1	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
python-cryptography	source	(unstable)	49.0.0-1

Notes

https://github.com/pyca/cryptography/security/advisories/GHSA-jwv3-5hgf-82ww
https://github.com/pyca/cryptography/pull/14960
Fixed by: https://github.com/pyca/cryptography/commit/4a12cf49675a184e47f912b00b04f3a629283582 (49.0.0)